Pump governor



Jan. 21, 1958 B. J. FEJEDELEM 2,820,414

PUMP GOVERNOR Filed July e, 1954 I Iii/a. j.

IN V EN TOR.

niteci This invention relates to governors for useonpurnp's, particularly centrifugal pumps as used on fi're,trucks',..and relates toF au improved device for pressure maintenance' therein.

4In the employment of centrifugal pumpsoperated by a' drivingmeans. such as a motor or engine, a problem in many applications of such pumps is the maintenance of a pressure which is relatively constant regardless of the demand upon the pump. This problem is. particularly acute in the case of fire trucks, wherein the usual arrangement is that the internal' combustion engine used for the propulsion of the truck itself is also used for drivingthe pump at the. scene of the fire. The pumps are generally of the centrifugal type and are generally multiple and arranged so that they can be connected in series or parallel. The usual arrangement is. that several fire hoses are fed by the same pump, and a problem arises whenever a nozzle is opened or, more particularly, suddenly closed, forexample by a fireman operating .one of the nozzlesattached to one of. the hoses. When a nozzle is4 suddenly closed, in theabsence of" any pump governingmechanism thepressure in the system will rise, and this is often sufcient to cause a reaction atthe .other nozzle being operated of"suiicient magnitudevto throw a fireman froml a ladder or. the. like. Similarly, when a nozzle is open, the. pressure in a multiple hose system tends to be lowered, and pressure mustbe restored'in order for the fire to be combated with maximum efficiency.

Otherdifiiculties arise when shifting from'pa-rallel feed toseries feed, wherein it is desired to regulate atah'igher pressure for the series feed. Any satisfactory pump regulator must be capable of operationlof a large range of pressures, accordingly, and this taxes some regulators beyond their mechanical limits.

Many devices have been. described for. themaintenauce of a constant pressure under the conditions described.` For the most part, they are quite complicated mechanically,` and there has been -a continuing need'for an improvement in the performance of available pump regulators.

Anobject of fthe invention is to provide an improved.

pump regulator for pressure regulation of acentrifugall pump. maintained by adrivingfmeans.

Another object of the invention is.to` providewaiireI pump governor' of simple design.

Another objectofthe invention is to. provide.entireY pump-.governor which canbe integral with the throttlef` mechanismusedfor control. of .the'enginer during propul-l sion:` ofthe:` truck, and `not 'interfere therewith, .yetrbeilngz instantly available for'pump: pressure regulation' during the loperation ofthe pump;

Anotherobject of theinventicm is' to provide-a pump' governor' readily adaptable to a rangeY ofpressures= en;4

counterediinl both parallel andseries' operations of'fre" pumpsa Another object of the invention is to provide a fire pump'- Patent C ICC Fig.` 3 shows a cross-section. through the assembly of.`

Fig; 2 through' the planes indicated by the dashed line 3-3 in Fig. 2.

Fig; 4 showsa modification of the method' of mountingmy novel governor on a carburetor.

Coming' now t'o a description.A of my novel governor,l

reference' is had to'the drawings. In'Fig. 1, 16 indicates a carbureto'nwhich it will be understood is attached to the' engine. ofa fire truck; 11 is .the throttle shaft of the carburetor; the butterfly' valve itself'is indicated by dotted lines', inzFig's. 1 and 2l lt will be observed that as the throttle shaftis rotated inA a' counterclockwise direction, the butterfly valve is opened.

Now in Fig. l, I2 indicates' a rod attached to the footthrottle used in drivingthe truck; and 13 represents the hand control wire'which is conveniently fixed to the instrument board of" the fire truck, and is used for control of'the throttle' of the engine during the pumping operationat the scene of a fire. A clevis fitting 14 receives both the footirodv 12' and the hand'wire 13; and a retracting spring 15 biases thethrottleV in' the closed position.

The clevis fitting'14 is attached to an operating rod 16 which in'turn isi attached' to' the piston rod 17 of the governor assembly bymeans of a simple fitting 1B.

The pistonrod'l'/ isfitted into'a' cylinder assembly 19', which is shown in cutaway detail in Figs'. land 2.` The cylinder 19 is'carried` by a supporting fitting- 20, which' carries a horizontal rod 21 which passes througha'slottedlever 22, which in turn is attached to thethrottle shaft1`1`.

In the embodiment shown in' Figs. l, 2l and 3, the weight of the piston and cylinder assembly is borne by a linkl 23, which inr the embodimentshown in Fig; l is attached'to the carburetor body by. a' fixed bracket 24', ands which in the embodiment shown inFig's; 2 and 34 is atta'ched to the carburetorbody through a substantially' horii zontal linkage 25.

Itwill ble seen thatretractingof'the operatingr'od 16,

which may be brought about'through the action ofeither! the foot rod`12 or the hand wire 13, will serve to. open the throttle of the butterfiy valve of the carburetor, and thus, if the` engine is running, increase its'speed.

Now attached to one end' of the cylinder' assembly is'a fiexible hose 26?. This is connected to the downstream.

side of the pump, so that it lreceiveswaterund'er the fluid' pressuredeveloped' by the pumps. The connectionV is prefera'bly made' through' a fitting having greater resistance to iiow in' one direction vthan another, whichis indicated in Fig. 1v by the che'clvalve andbyp'ass'assembly 27'. The tubing 2S? leadsfto .'theipump mechanism 138?.

Suppose tha-tthe pumps: are started; The engin'eisthen accelerated. by operation` of the hands control wire' 13;` which moves rodvl. to''the right, thereby opening thev Ther wide-open-throttle position is shown in.V Figi. Nowfsupposethat atthisparticular. setting .of the.y engine,.. the pump pressure is. too great, which might be.V caused for example by-shutting off some ofthe. tire hosesV throttle.y

at the nozzles.. thereof. Water will be forced through tubing ZSandiieXible hose 26 into the piston holderiand cylinder assembly 1'9. This will exert a force against the compression" spring 29'Which' is contained'in' the'cylinder. The cylinder will then move' outwardly or to the left;

with respect to' thepiston, and thusopcrateto closethe"P throttle: Thus; a governing action is' obtained. Shuld' the pressure drop, for example as the result of opening one or more re nozzles, then the fluid pressure inside of the cylinder assembly 19 will be reduced, which will allow spring 29 to expand, and will thus move the cylinder to the right with respect to the piston, thus opening the throttle. The engine speed can be set at any desired value, by operating the hand control, and changes in pump pressure occurring thereafter will be offset and the desired pressure regained by the automatic operation of the governor in the manner just described.

A preferred embodiment of the piston and cylinder construction may be clearly seen in Fig. 2, wherein ,30 designates a leather cup of the usual type. A slotted boss 31 is provided for the end of the piston to abut, so that even when the spring is fully expanded, a free passage for flow of water into the cylinder assembly is provided.

In the embodiment shown in Figs. 2 and 3, the link 23 which carries the weight of the governing assembly is attached to a horizontal linkage 25, which may be raised or lowered within limits by a bent lever 32, the position of which is adjustable by set screws 33 and 34. Where regulation at greatly differing pump pressures is desired, the operating range of the regulating action can be shifted by raising or lowering linkage 25 by suitable adjustment of lever 32 and set screws 33 and 34. For many installations, however, the simpler lever arrangement shown in Fig. l suiiices.

The method of supporting the governor assembly wherein a separate link 23 is used as in the embodiments of Figs. 1 and 2, is preferable for use where the governor is installed on an existing engine. This is for the reason that in the average carburetor, the throttle-shaft bearings are not constructed for heavy duty, often being merely drilled in the die-cast body of the carburetor itself. However, where the bearings of the carburetor throttle shaft are adequate to carry the weight involved, the simplied assembly shown in Fig. 4 sumces, and serves to eliminate a number of mechanical parts. It will be seen that in the embodiment of Fig. 4 the governor assembly 19 is supported directly by the lever 22 attached to the throttle shaft, and the entire weight of the governor is placed upon the throttle shaft bearings.

I have found that in many instances, if free access of water from the pumps is permitted to the governor cylinder, the pressure control may be subject to repeated fluctuations, often termed hunting I have found that an effective way of controlling this tendency and of obtaining perfectly smooth response is to include an assembly, shown as 27 in Fig. l, in the water supply line to the governor, which permits relatively free passage of water to the cylinder 19, but provides relative restraint to ow of water in the opposite direction, that is, out of cylinder 19, and back to the pump. This is readily accomplished by providing a check valve 35, which may be of common and simple construction, with the check action so arranged that the valve is open in the direction away from the pumps, and toward the governor. The check valve is bypassed by a needle valve 36, which is set with the needle slightly open, thus offering a restriction to return flow, since for flow in this direction the check valve will be closed. Thus, if pump pressure increases suddenly, as caused for example by the sudden shutting ofi' of hose nozzles, then the throttle action is virtually instantaneous because Water from the pumps flows without hindrance into cylinder assembly 19. However, if the pump pressure drops suddenly, as caused for example by the opening of hose nozzles, then the response of the engine is much slower, because in order for the engine to be accelerated, water must leave the cylinder 19 which it can do only by passing through the needle valve 36.

It will be seen that the invention accomplishes its objects. It will also be observed that the invention is a broad one, and it is desired to claim the invention broadly within the scope of this specification and appended claims,

4 particularly since many modifications of detail can be made, all within the scope thereof.

What I claim is:

1. In a fire truck including an engine, a carburetor attached thereto, rotatable throttling means attached to said carburetor, and including a throttle shaft, yand at least one centrifugal pump operatable by said engine: the combination of a lever arrn attached to said throttle shaft; a cylinder pivoted to said lever arm; a piston within said cylinder; a spring within said cylinder and urging said piston to empty said cylinder; connecting means attaching said piston to a positionable hand control; and a flexible hose means communicating between said cylinder and said pump.

2. In a tire truck including an engine, a carburetor attached thereto, rotatable throttling means attached to said carburetor, and including a throttle shaft, and at least one centrifugal pump operatable by said engine: the combination of a lever arm attached to said throttle shaft; a cylinder pivoted to said lever arm; a piston within said cylinder; a spring within said cylinder and urging said piston to empty said cylinder; connecting means attaching said piston to a positionable hand control; a fluid passage means communicating between said cylinder and said pump and including a by-passed check valve.

3. In a governor for regulating pump pressure in a tire engine including an internal combustion motor, at least one pump, a butterfly valve regulating air input to said motor; and a positionable throttle control; the combination of a link pivotally fixed to said motor and rotatable in a substantially vertical plane; a forked lever operating said buttery valve; a shaft attached to the movable end of said link and engaging said forked lever; cylinder suspension means `attached to the moving end of said link; a cylinder suspended by said suspension means; a piston within said cylinder including fluid sealing means at the end thereof Within said cylinder; a compression spring urging said piston into said cylinder; a rod means connecting said piston and said positionable control; a llexible hose means connected to said cylinder; and a tubing means connecting said hose means to said pump.

4. The combination of claim 3 wherein uid throttling means are interposed between said pump and said cylinder of a character permitting free flow of fluid to said cylinder but restricted flow of fluid from said cylinder.

5. The combination of claim 3 wherein said cylinder suspension carrying link is pivoted to a substantially horizontal lever which in turn is pivotally attached to said ymotor at a point horizontally displaced from the pivotal connection of said link and said lever, and adjusting means for raising and lowering said lever.

6. Throttle control means for operatively connecting a positionable hand control and a hydraulic centrifugal pump driven by an engine having a carburetor provided with rotatable throttling means attached thereto, comprising: a lever arm for attachment to said rotatable throttling means; a cylinder pivoted to said lever arm; a piston within said cylinder; a spring within said cylinder and urgi'ng said piston to empty said cylinder; connecting means for attaching said piston to said positionable hand control; and a flexible hose means for communicating between said cylinder and said pump.

7. Throttle control means for operatively connecting a. positionable hand control and a hydraulic centrifugal pump driven by an engine having la carburetor provided with rotatable throttling means attached thereto, comprising: a lever arm for attachment to said rotatable throttling means; a Kcylinder pivoted to said lever arm; a piston within said cylinder; a spring within said cylinder and urging said piston to empty said cylinder; connecting means for attaching said piston to said positionable hand control; a iluid passage means including a by-pass check valve for communication between said cylinder and saidl pump.

8. Throttle control means for operatively connecting a positionable hand lcontrol and a ireenginepumpoper ating internal combustion motor air-input-regulating buttertly valve: in combination, a pivot for xation with respect to said buttery valve; a link attached to said pivot and rotatable thereabout; a forked lever for attachment to and operation of said butterily valve; I'a shaft attached to the movable end of said link and engaging said forked lever; cylinder suspension means attached to moving end of said link; a cylinder suspended by said suspension means; a piston within said cylinder including fluid sealing means at the end thereof within said cylinder; a compression spring urging said piston into said cylinder; a rod means for operatively connecting said piston and said positionable hand control; a flexible hose means connected to said cylinder; and a tubing means for connecting said hose means to said pump.

9. The combination of claim 8 wherein there is operatively connected with said tubing means fluid throttling means of a character permitting free flow of fluid to said cylinder but restricted ilow of uid from said cylinder.

10. The combination of claim 8 wherein said cylinder suspension means is pivoted to a substantially horizontal lever which is in turn pivotally attachable to said motor at a point horizontally displaced from the pivotal position of said link and said lever, and adjusting means for raising and lowering said lever.

References Cited in the le of this patent UNITED STATES PATENTS 

